1. Field of the Invention
The present invention relates to a remotely controllable radio selective calling receiver having a function to display a message which has been transmitted, and more particularly to a radio selective calling receiver which can be remotely controlled to produce reception inhibition and permission settings.
2. Description of the Related Art
Individual receivers of a radio selective calling system are remotely controlled by the network supervisor. For example, if a receiver is to be dropped as a selective calling receiver out of service due to a payment failure, then the network supervisor remotely controls the receiver to set it to a reception inhibition status. After a payment, the network supervisor may remotely control the receiver to set it to a reception permission status for recovery from the reception inhibition status. Specifically, the network supervisor remotely controls the receiver by determining beforehand control information which represents a reception inhibition or permission and transmitting a selective calling number and then control information for the receiver that is to be controlled. When the receiver receives a control information, the receiver changes its operation status in response to the control information.
Control information is transmitted to a receiver having a function to display a message by being either added to selective calling information transmitted from a network base station in the same format as a message or included in a message in present selective calling information. Code systems used for information transmitted for displaying messages include a code system for displaying alphanumeric characters as 7-bit words, a code system for displaying alphanumeric and kana (Japanese phonetic alphabet) characters as 8-bit words, and a code system for displaying numeric characters ("0"-"9" and several special characters) as 4-bit words. Since the 7-bit and 8-bit code systems contain redundant code characters which are not used for displaying messages, it is possible to assign such redundant code characters to control information and a header. However, no redundant code characters at all are available in the 4-bit code because all 16 code characters thereof are used for displaying messages. Consequently, conventional radio selective calling receivers which display only numeric characters are not remotely controllable to make reception inhibition and permission settings.
Japanese patent laid-open No. 225034/87 (JP, A, 62-225034) gazette discloses a selective calling receiver responsive to a plurality of selective calling numbers, one of which is used to remotely control the selective calling receiver to make a reception inhibition setting. The disclosed selective calling receiver is, however, not designed to receive any information that follows a selective calling number, and not capable of displaying messages. Therefore, the selective calling receiver is unable to make a reception permission setting under remote control after a reception inhibition setting has been made. Japanese patent laid-open No. 31321/88 (JP, A, 63-31321) gazette discloses a selective calling receiver responsive to a plurality of selective calling numbers which prevents an alarm sound from being generated for each selective calling number in response to operation of a switch on the receiver. With this selective calling receiver, however, no reception is inhibited by remote control, and no message from a transmission site is displayed. Japanese patent laid-open No. 95632/89 (JP, A, 1-95632) gazette discloses a selective calling receiver responsive to a plurality of selective calling numbers and remotely controllable to make a reception inhibition setting under remote control. Japanese patent laid-open No. 141732/92 (JP, A, 3-141732) gazette discloses a radio selective calling receiver which can be controlled to start or stop a certain operation in response to control information which follows a selective calling number addressed to the radio selective calling receiver. According to the arrangements disclosed in the above gazettes, it is possible to establish a reception inhibition setting or the like for a selective calling receiver, and shorten a processing time to reduce current consumption and improve controllability. However, because these disclosed schemes are not applicable to selective calling receivers which display only numeric characters, these radio selective calling receivers are not remotely controllable for producing reception inhibition and permission settings.